Wireless transmission of energy is inconvenient and inefficient, particularly so at longer distances. For example, one type of wireless battery recharging system requires that a cellular telephone be physically placed atop a charging mat. For such a device, the requirement for close proximity between the device and the charging mat tends to nullify the benefit of eliminating a wired connection. A typical recharging mat is incapable of wireless power transmission at a distance greater than a few centimeters.